Evaluating physical functioning in critical care: considerations for clinical practice and research.

The evaluation of physical functioning is valuable in the intensive care unit (ICU) to help inform patient recovery after critical illness, to identify patients who may require rehabilitation interventions, and to monitor responsiveness to such interventions. This viewpoint article discusses: (1) the concept of physical functioning with reference to the World Health Organization International Classification of Functioning, Disability and Health; (2) the importance of measuring physical functioning in the ICU; and (3) methods for evaluating physical functioning in the ICU. Recommendations for clinical practice and research are made, along with discussion of future directions.